1. Iberoamerican Cochrane Network; Valencia Venezuela
2. CIBER Epidemiología y Salud Pública (CIBERESP); Iberoamerican Cochrane Centre, Biomedical Research Institute Sant Pau (IIB Sant Pau); Sant Antoni Maria Claret 167 Pavilion 18 Barcelona Catalunya Spain 08025
3. Copenhagen Trial Unit, Centre for Clinical Intervention Research, Department 7812, Rigshospitalet, Copenhagen University Hospital; Cochrane Hepato-Biliary Group; Blegdamsvej 9 Copenhagen Denmark DK-2100
4. "George Gennimatas" General Hospital; Thessaloniki Greece
5. University of Minnesota; Department of Medicine; 420 Delaware Street SE Mayo Mail Code 195 Minneapolis MN USA 55455